基于SPH方法的电场下液滴动力学数值模拟

Numerical Simulation of Droplet Dynamics under Electric Field Based on SPH Method

建立了适用于电场作用下液滴动力学的光滑粒子流体动力学(SPH)模型,并验证了模型的准确性。运用此模型研究了电场强度对液滴聚并时间的影响。结果表明:电场强度增加,液滴接触时的极化变形程度增加,不利于液滴融合,当电场强度过高时,液滴会发生破碎;当电场强度达到2860 kV/m时,液滴粒子迅速向边壁移动,液滴在其端部向四周扩张之前,已经发生破碎,液滴的破碎时间趋于稳定;当电场强度达到3580 kV/m时,液滴两端受到了更大的电场力,液滴被迅速拉伸变形,液滴从中间部位直接破碎为左右两个子液滴;当液滴直径达到6 mm时,固壁边界抑制液滴变形,液滴的破碎时间迅速上升。

An smooth particle hydrodynamics(SPH)model suitable for droplet dynamics under the action of an electric field was establishd,and the accuracy of the model was verified.This model was used to study the effect of electric field intensity on droplet coalescence time.The results showed that as the electric field intensity increased,the degree of polarization deformation during droplet contact increased,which was not conducive to droplet fusion.When the electric field intensity was too high,the droplets would undergo fragmentation.When the electric field strength reached 2860kv/m,the droplet particles moved quickly to the edge wall.Before the droplet expanded to the surrounding area at its end,it had already broken,and the breaking time of the droplet tended to stabilize.When the electric field strength reached 3580kV/m,the two ends of the droplet were subjected to greater electric field forces,and the droplet was rapidly stretched and deformed.The droplet breaked directly into two sub droplets on the left and right from the middle part.When the diameter of the droplet reached 6mm,the suppression of droplet stretching deformation by the solid wall boundary was significantly enhanced,and the breaking time of the droplet increased rapidly.